Laboratory Studies

No pathognomonic laboratory test for benign positional vertigo (BPV) exists. Laboratory tests may be performed to rule out other pathology.

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Imaging Studies

Currently, no imaging study can demonstrate the presence of otoliths.

Head CT scanning or MRI is indicated if the diagnosis is in doubt.

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Other Tests

Although most patients with benign positional vertigo (BPV) have posterior semicircular canal involvement, some patients have horizontal canal involvement. This canal should be suspected if the patient has bilateral symptoms during the Hallpike test. Use the Roll test to formally diagnose horizontal canal BPV, and use the bar-b-que treatment to treat horizontal canal BPV.

Roll test

Have the patient lie in the supine position on the gurney. Unlike the Hallpike test, the head does not need to hang over the edge of the gurney.

Turn the patient's head 90° to one side. The patient should experience a reproduction of symptoms and the presence of horizontal nystagmus. The fast phase should beat toward the earth (geotropic).

Now, turn the patient's head 180° (or 90° to the opposite side). The patient should again experience a reproduction of symptoms and the presence of horizontal nystagmus. The fast phase again beats toward the earth (note that it has changed direction). This is known as direction-changing nystagmus (nystagmus that changes direction based on turning the head) and is different from gaze-evoked nystagmus (which is nystagmus that changes direction depending on where the patient is looking, as in Dilantin toxicity).

Note that both sides will have nystagmus and a reproduction of symptoms, but one side will be much more symptomatic (and demonstrate stronger nystagmus) than the other side. This is considered the involved side.

A positive Roll test should be treated with the bar-b-que treatment (see Treatment and the video below).

Bar-b-que maneuver. This maneuver is used to treat horizontal canal benign positional vertigo. In this example, the right horizontal canal is being treated. Each position should be held at least 20-30 seconds.

Head-thrust test (head-impulse test)

The head-thrust test is used to diagnose vestibular neuritis and labyrinthitis.

In this test, the patient is told to look at the examiner's nose. The examiner places both his or her hands on the patient's head and rapidly turns it approximately 10-15° to one side. If the vestibular apparatus is functioning properly, the patient will be able to maintain his or her focus on the examiner's nose. If the vestibular apparatus is not working properly, the patient's eyes will deviate to the side and then quickly jerk back to view the examiner's nose. This jerking eye movement is called a saccade and indicates a positive head-thrust test. As a general rule, a positive head-thrust test rules in a peripheral (and hence benign) cause of vertigo. There are reported cases, however, of positive head-thrust tests in central causes of vertigo.

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Procedures

The Hallpike test, along with the patient's history, confirms the diagnosis of BPV. See Physical for details of this procedure.

The modified Epley maneuver is used to treat posterior canal BPV (see Treatment as well as the video below for a demonstration).
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Epley maneuver. In this example, the left posterior semicircular canal is being treated. In this clip, the maneuvers are performed quickly. In a real patient, each position should be held for at least 30 seconds or until resolution of the nystagmus and vertigo.

Epley maneuver. Move the patient back in the gurney such that when he lies down, his or her head will hang over the edge of the gurney. Emphasize to the patient to keep his or her eyes open during each position so that nystagmus can be observed. Lower the guardrails of the gurney on the opposite side from which the patient's head is turned.

Epley maneuver. Turn the patient's head 45° to the side that had the most prominent symptoms during the Hallpike test. In this example, the patient's head is turned 45° to the left. With both hands holding the patient's head, gently lay the patient down in the supine position with the head hanging over the edge of the bed. Note: Each maneuver does not need to be performed rapidly. The Epley maneuver is positional, not positioning.

Epley maneuver. The patient's head should be at 45° and hanging off the edge of the bed. Observe the patient's eyes and look for torsional nystagmus. Keep the patient in this position for at least 30 seconds or until the nystagmus or symptoms resolve.

Epley maneuver. Because the patient's head will be turned 90° in the other direction, the physician needs to move to the head of the gurney and regrip the patient's head so that the fingers are pointing toward the patient's feet.

Epley maneuver. Turn the patient's head 90° in the opposite direction (in this case, the patient's head is now facing to the right). Again, observe for nystagmus and hold this position for at least 30 seconds or until nystagmus or symptoms resolve.

Epley maneuver. Close-up view of step shown in Media file 6.

Epley maneuver. Ask the patient to turn onto his or her shoulder.

Epley maneuver. Guide the patient's head down so that he or she is looking at the ground. Again, wait for at least 30 seconds.

Epley maneuver. Close-up of view shown in Media file 9.

Epley maneuver. The patient's head needs to be regripped again. Then, the patient needs to sit up with the legs hanging over the side of the gurney (which is why the guardrails need to be lowered before the start of the procedure).

Epley maneuver. The patient is now sitting upright.

Epley maneuver. Move the patient's head slightly forward. This completes the Epley maneuver. The maneuver may be performed multiple times.

Hallpike test. In this example, the right posterior semicircular canal is being tested. Note that the head extends over the edge of the gurney. The thumb can be used to help keep the eyelids open since noting the direction of the nystagmus is important.

Epley maneuver. In this example, the left posterior semicircular canal is being treated. In this clip, the maneuvers are performed quickly. In a real patient, each position should be held for at least 30 seconds or until resolution of the nystagmus and vertigo.

Semont maneuver. Generally reserved for the cupulolithiasis form of benign positional vertigo, in which the otoliths are attached to the cupula of the semicircular canal. This maneuver has to be performed rapidly to be effective, and it is not recommended in elderly persons. In this example, the right posterior semicircular canal is being treated.

Bar-b-que maneuver. This maneuver is used to treat horizontal canal benign positional vertigo. In this example, the right horizontal canal is being treated. Each position should be held at least 20-30 seconds.